The present invention relates generally to devices for dispensing plastic fasteners and more particularly to a reactor plate assembly for a device for dispensing plastic fasteners.
In U.S. Pat. No. 4,039,078 to A.R. Bone, which is incorporated herein by reference, there are disclosed several different types of plastic fasteners, or attachments, which are fabricated as part of continuously connected ladder stock. In each instance, the fastener has an H-shape, and the ladder stock is formed from two elongated and continuous plastic side members coupled together by a plurality of plastic cross links, the cross links preferably being equidistantly spaced. The stock may be produced from flexible plastics material including nylon, polypropylene and other similar materials by molding or by stamping. Either manually or with the aid of specifically designed devices, individual fasteners may be dispensed from the ladder stock to couple buttons to fabric, merchandising tags to articles of commerce, or, in general, any two desired articles. In those instances where the dispensing device has dual needles, the attachments severed from the stock can be used like staples to secure objects and items.
Devices for dispensing plastic fasteners are well known in the art. Plastic fastener dispensing devices are commonly used to sever individual plastic fasteners from continuously connected ladder stock and to attach such individual plastic fasteners to items, such as socks. Devices for dispensing plastic fasteners often comprise a frame which includes a base, a neck, a housing, and an arm onto which a reactor plate is mounted. Devices for dispensing plastic fasteners also typically comprise a hollow slotted needle which is mounted onto a head member that can be downwardly displaced by a crank arm.
The reactor plate for the device serves as a support surface, or anvil, on which the items to be coupled by a plastic fastener are placed. The reactor plate typically includes a top surface, a bottom surface and an opening formed in the top surface. The opening is typically circular in lateral cross-section and is relatively small in size (approximately 0.25 inches in diameter).
In use, the items to be attached by a plastic fastener are placed on the reactor plate. Activation of the crank arm drives the hollow slotted needle down through the items to be attached and into the opening formed in the top surface of the reactor plate. With the needle disposed through the items and into the opening in the reactor plate, further activation of the crank arm downwardly projects an ejector rod which is disposed inside the hollow needle. Downward projection of the ejector rod urges a cross-bar of the plastic fastener through the articles to be coupled.
In U.S. Pat. No. 5,433,366 to C. L. Deschenes, which is incorporated herein by reference, there is disclosed a device for dispensing plastic attachments of the type which are formed as part of a roll of continuously connected ladder stock. In one embodiment, the device includes a pair of hollow slotted needles each having a tip, a rear end and a longitudinal axis. A feed wheel, placed proximate to the rear ends of the pair of needles, is used to feed individual attachments of a roll of ladder stock into the pair of needles through their respective rear ends at angles relative to the longitudinal axes thereof. Once inserted into the needles, an attachment is severed from the remainder of the ladder stock by a knife and is then expelled from the needles by a pair of ejector rods movable along the longitudinal axes of the pair of needles. Because attachments are fed into the pair of needles at angles relative to their longitudinal axes, no shuttling of the needles between an attachment feeding position and an attachment ejecting position is required. The pair of needles, the feed wheel, the knife, and the pair of ejector rods are all mounted on a vertically movable head member. An electric motor assembly is used to move the head member between an attachment dispensing position and a withdrawal position. The vertical movement of the head member drives the operation of the feed wheel, the knife and the ejector rods.
Although devices of the type described above have performed reasonably well in dispensing plastic fasteners, it has been found that these types of devices often experience two notable drawbacks.
As a first drawback, it has been found that, on occasion, the reactor plate provides inadequate support for coupling together the desired articles. In particular, it has been found that, as the needle pierces through the items during the coupling process, articles which are manufactured out of a thin material are often pushed down into the opening in the reactor plate. As a result, the needle is unable to pierce all the way through the items, thereby preventing the device from properly coupling the desired articles with a plastic fastener.
As a second drawback, it has been found that, on occasion, the needle does not properly align itself down into the opening formed in the reactor plate. Specifically, as the needle is displaced downward through the items, the fabric, or weave, of the items often bends, or attenuates the needle, thereby displacing the needle laterally. As a consequence, the needle is often misaligned and, accordingly, will abut against the top surface of the reactor plate rather than project down into the relatively small opening in the reactor plate, thereby preventing the device from properly coupling the desired articles with a plastic fastener.